High Performance Asymmetric Supercapacitors Based on Dual Phosphorus (P) and Nitrogen (N) co-Doped Carbon and Graphene-Polyaniline Electrodes

Abstract

We report an asymmetric type hybrid supercapacitor device with ultrahigh-energy density by employing a dual phosphorus and nitrogen co-doped carbon (PNDC) and a graphene (G)–polyaniline (PANI) nanocomposite electroactive electrodes. Dual-doped carbon is synthesized by the microwave assisted technique and G-PANI was synthesized by the chemical oxidative polymerization technique. An asymmetric PNDC/G-PANI electrodes with ionic liquids (IL) as electrolytes in supercapacitor are found capable of increasing the operating voltage up to 4 V and electrodes with aqueous electrolytes in supercapacitor are capable of increasing the operating voltage up to 2 V. The size-uniform porous nanostructures of PNDC and G-PANI provide a continuous electron pathways and facilitate short ionic transportation process. Further, IL increases the wettability of the electrodes and exhibited ultra-high energy density of 114 Wh/kg and 13.7 kW/kg power density at a 2 A/g current density. Therefore, the asymmetric type hybrid supercapacitor based on G-PANI nanocomposite and microwave assisted PNDC electrodes is a cost effective ultra-high energy density supercapacitor with high rate capability.